Trust Investments (Fair Values And Gross Unrealized Gains And Losses For The Securities) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019
Rabbi Trust [Member]
Schedule of Trust Investments [Line Items]
Cost	$ 238		$ 228
Gross Unrealized Gains	28		18
Gross Unrealized Losses	0		0
Fair Value	266		246
Rabbi Trust [Member] | Domestic Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	21		21
Equity Securities, FV-NI, Unrealized Gain	10		7
Gross Unrealized Losses	0		0
Fair Value	31		28
Rabbi Trust [Member] | International Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	0		0
Equity Securities, FV-NI, Unrealized Gain	0		0
Gross Unrealized Losses	0		0
Fair Value	0		0
Rabbi Trust [Member] | Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	21		21
Equity Securities, FV-NI, Unrealized Gain	10		7
Gross Unrealized Losses	0		0
Fair Value	31		28
Unrealized Gains (Losses) on Equity Securities still held	4
Rabbi Trust [Member] | Government Obligations [Member]
Schedule of Trust Investments [Line Items]
Cost	94		100
Gross Unrealized Gains	6		4
Gross Unrealized Losses	0		0
Fair Value	100		104
Rabbi Trust [Member] | Corporate Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	123		107
Gross Unrealized Gains	12		7
Gross Unrealized Losses	0		0
Fair Value	135		114
Rabbi Trust [Member] | Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	13
Cost	217		207
Gross Unrealized Gains	18		11
Gross Unrealized Losses	0		0
Fair Value	235		218
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
Cost	1,990		1,858
Gross Unrealized Gains	523		374
Gross Unrealized Losses	(14)		(18)
Fair Value	2,499	[1]	2,214
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Domestic Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	519		425
Equity Securities, FV-NI, Unrealized Gain	305		238
Gross Unrealized Losses	(3)		(4)
Fair Value	821		659
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | International Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	388		400
Equity Securities, FV-NI, Unrealized Gain	152		103
Gross Unrealized Losses	(9)		(11)
Fair Value	531		492
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Equity Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	907		825
Equity Securities, FV-NI, Unrealized Gain	457		341
Gross Unrealized Losses	(12)		(15)
Fair Value	1,352		1,151
Unrealized Gains (Losses) on Equity Securities still held	184
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Government Obligations [Member]
Schedule of Trust Investments [Line Items]
Cost	555		563
Gross Unrealized Gains	27		16
Gross Unrealized Losses	(1)		(2)
Fair Value	581		577
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Corporate Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Cost	528		470
Gross Unrealized Gains	39		17
Gross Unrealized Losses	(1)		(1)
Fair Value	566		486
PSEG Power LLC | Nuclear Decommissioning Trust (NDT) Fund [Member] | Debt Securities [Member]
Schedule of Trust Investments [Line Items]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	37
Cost	1,083		1,033
Gross Unrealized Gains	66		33
Gross Unrealized Losses	(2)		(3)
Fair Value	$ 1,147		$ 1,063

[1] The NDT Fund Investments table excludes foreign currency of $2 million as of December 31, 2020,         which is part of the NDT Fund.